1. Field of the Invention
The invention relates to roller-flanging (also known as spin flanging) cylindrical bodies, at least in one edge region, with a device having a plurality of flange rollers that are rotatably seated in a receptacle and roll along the cylindrical body to be reshaped, forming a flange with their contour.
2. Background Information
Flanging is the bending of an edge of a sheet metal piece, e.g., for work piece reinforcement, or in order to blunt the edge. In can bodies to be flanged, for example, flanging is a preparatory process in which the cylinder jacket of the can body is reshaped over its entire circumference in the region of its edges. The shaped flange is particularly specified by the flange radius (R) that adjoins the final contour of the can and an end region of the flange which is principally unbent and is, for the most part, oriented perpendicular to the longitudinal cylinder (can) axis.
Flange rollers serve to form the flange in the can body. These flange rollers rotate and are disposed in a common receptacle on a circle whose diameter is selected based on the diameter of the can to be flanged.
The receptacle rotates relative to the can body about an axis of rotation corresponding to the longitudinal axis of the can body. A limiting ring encompasses the flange rollers with its inner jacket and is seated coaxially to the longitudinal axis of the can body.
The inner diameter of the limiting ring serves to define the maximum flange diameter or circumference, as follows. The can body, also referred to as a can body blank, is placed above the flange rollers, and the can body and the set of flange rollers are guided closer together. The bottom end of the can will be bent outwardly until it has a diameter that corresponds to the inner diameter of the limiting ring.
There is a gap into which flanged material or burr of the treated work piece (flanged can) can extend located between the limiting ring and the flange rollers. However, this can result in coatings of the flanging device parts becoming damaged. Moreover, the threat exists of the can body being uncontrollably carried along by the flange rollers, with the consequence of deformation and pronounced unevenness of the resulting flange.